Process of producing motor fuels from hydrocarbon oils



' May 28, 1935. M, C APPEL L 2,002,729

PRQCESS OF PRODUCING MOTOR FUELS FROM HYDROCARBON OILS Filed May 28,1954 INVENTOR Hedfer Patented May 28, 1935 UNITED STATES PROCESS OFPRODUCING MOTOR FUELS FROM HYDROCARBON OILS Marvin L. Chappell, Watson,Calif.

Application May 28, 1934, Serial No. 727,972

8 Claims.

This invention relates to an improved method of processing hydrocarbonoils, such as naphtha, lamp oil distillates, gas oil stock, or otherpetroleum oil stocks, to produce by partial dehydrogenation, crackingand reforming, a motor fuel with high anti-detonating characteristics,and one which may be mixed or blended with other gasoline stocks toimprove the anti-detonating characteristics thereof, and/or to produce amotor fuel with high anti-detonating characteristics and a marketablefuel oil from petroleum oil residuums or fuel oil stocks.

This application is in part a continuation of my pending applicationSerial No. 611,789, filed May 17, 1932, now U. S. Patent 1,984,519, forProcess of producing motor fuel from hydrocarbon oils.

Briefly stated, my invention comprises passing hydrocarbon oil through aheating zone under superatmospheric pressure and heating the oil to acracking temperature; passing the heated oil from the heating zone, withor without reduction of pressure, into a vaporizing zone and vaporizingthe oil or a regulated portion thereof; continuously separating andremoving the unvaporized oil from the vaporizing zone to produce amarketable fuel oil; mixing the vaporized portion of the oil in theupper section of the vaporizing zone with an aeriform fluid containingfree oxygen of less concentration than atmospheric air, preferablyranging from 5 to approximately 18 per cent by volume free oxygen, inquantities suflicient to reduce the hydrogen content of the oil topreferably approximately 14.3 per cent by weight and to not less than 9per cent by weight; passing the mixture of vaporized oil and aeriformfluid from the upper section of the vaporizing zone into a reaction zoneand producing, by further cracking and reforming, oils of thecarbocyclic series, such as mixtures of hexahydrobenzol,hexahydrotoluol, I hexahydroxylol, benzol, toluol, xylol, etc., whichare oils having antidetonating characteristics when used as a motorfuel; continuously passing the dehydrogenated, cracked, reformed oilsand aeriform products, as

produced, from the reaction zone into a fractionating zone, andseparating, by fractionation, aeriform products, a motor fuel and ahigher boiling distillate from a residual oil, and continuouslyreturning the higher boiling oil, separated from the other fractionatedproducts, to an upper section of the reaction zone to be further crackedfor the further continuous production of motor fuel.

Processes of producing oils such as benzol, toluol, xylol, etc., by apartial combustion or dehydrogenation of hydrocarbon oils with air or inthe presence of air at elevated temperatures, are known in the art, suchas described in U. S. Patents 1,214,204 and 1,257,906, granted toFrederick W. Mann and Marvin L. Chappell, dated January 5 30, 1917 andFebruary 26, 1918 respectively, in which aromatic bodies and gas areproduced by passing hydrocarbon oil and air through a highly heated zonefilled with contact material, at a pressure less than atmospheric.Similar processes 10 are also known for the production of motor fuel bya partial'combustionof hydrocarbon oil with air at elevatedtemperatures, under atmospheric or superatmospheric pressure. By suchprocesses,

however, high losses are sustained due to the intensity of the oxidizingreaction or partial combustion of the 011 being processed, resulting inexcessive formation of carbon and gas, which may be as much as 40-50 percent of the hydrocarbon oil.

Now, I have discovered that these excessive losses due to the partialconversion of the hydrocarbon oil into carbon and gases by knownprocesses employing air, are principally due to the aeriform fluidcontaining too high an oxygen concentration; that by the employment ofan aeriform fluid containing free oxygen of lessconcentration thanatmospheric air, preferably approximately less than 18 per cent byvolume free oxygen, the time of the oxidizing reaction may be prolongedand modified toprevent to a high extent violent molecular disruption ofthe oil, and thereby decrease the formation of carbon and gaseousproducts, and that a higher boiling distillate may be separated from thereaction products and further cracked to increase the yield of motorfuel with high anti-detonating characteristics.

By this invention, an aeriform fluid having a free oxygen content ofless concentration than atmospheric air, preferably ranging fromapproximately 5 to 18 per cent by volume, is introduced with hot oilvapor into a contact reaction chamber, at areaction temperaturepreferably ranging from approximately 800 to 1300 F., in quantitiessufllcient to reduce the hydrogen content of the oil vapor to preferablyapproximately 14.3 per cent by weight and to not less than 9 per cent byweight, the extent of dehydrogenation depending upon the hydrogencontent of the oil treated and the products desired.

For example, if it is desired to produce a motor fuel having ananti-knock value or octane number of say 73 to 80, an aeriform fluidhaving a free oxygen content of say 10 per cent by volume would beintroduced in quantities sufiicient to reduce the hydrogen content ofthe oil to approximately 13 to 14.3 per cent, and a temperature would bemaintained in the reaction chamber ranging from approximately 800 to1100 F. If a motor fuel is desired having an "octane number of say to90, the quantity of aeriform fluid introduced, having a free oxygenconcentration of say 10 per cent, would be sufficient to reduce thehydrogen content of the oil to approximately 9 to 13'per cent, and thetemperature maintained in the reaction chamber would be fromapproximately 1100 to 1300 F.

The aeriform fluid employed may be air diluted with products ofcombustion, nitrogen, carbondioxide, carbon-monoxide, or other likegases, and the oxygen concentration is varied depending upon thepercentage of hydrogen contained by the oil being processed and theproducts desired. For example, if the oil to be processed has an averagehydrogen content of say 16 per cent by weight, the oxygen concentrationof the aeriform fluid would be maintained at preferably approximately 17per cent by volume, and for an oil having a hydrogen content of 14 to 15per cent, an oxygen concentration of preferably approximately 10 percent by volume would be used.

An object of the invention is to produce a motor fuel suitable for usein internal combustion engines with a high compression ratio, withoutrequiring the use of anti-knock compounds such as tetraethyl lead.

Another object of the invention is to provide a continuous system forproducing motor fuel with high anti-detonating characteristics, and

, then utilizing the motor fuel produced to blend with other gasoline ormotor fuel stocks lower in anti-knock value to improve theanti-detonating characteristics thereof.

Another object of the invention is to provide a process which may beregulated to produce a marketable fuel oil and a motor fuel of variablerange in anti-knock values with maximum yields, from crude petroleum oilor petroleum oil residua.

Various other objects and advantages of the present invention will beapparent from the description of the preferred form or example of theprocess embodying the present invention. For this purpose reference ismade to the accompanying drawing, in which there is illustrated a formof apparatus in which the invention may be performed. The drawingrepresents a diagrammatical view of apparatus in which the parts are insectional elevation.

In the drawing, 3 represents generally a tank for holding thehydrocarbon oil to 'be processed. Pipe l, controlled by valve 2,connects tank 3 to a source of the hydrocarbon oil supply. Pipe 4,controlled by valve 5, connects tank 3 near the bottom to the suctionside of pump 6. Pipe I connects the discharge side of pump 6 to heatexchanger 8. Pipe 9 connects heat exchanger 8 to heater coil II. Heatercoil II is stationed in the upper section of heater or furnace I8.Heater or furnace I0 is provided with an oil or gas burner I2.

Pipe I3, controlled by valve I4, connects heater coil II to reactionchamber I5. The upper section of reaction chamber I5 is shown filledwith contact material I8, such as checker brick work or hollow tile,supported by arch II, although an, open reaction chamber without contactmaterial may be employed. Reaction chamber I5 is preferably lined with afire resisting material, as shown by the numeral I8, which may be firebrick, fire resistant cement, or other suitable furnace lining known inthe art.

Pipe I9 connects reaction chamber I5 at the top to heat exchanger 8.Pipe 20, controlled by valve 2|, connects heat exchanger 8 tofractionating tower 22. Fractionating tower 22 is provided with bubbletrays 23 and a separator plate 62. Pipe 25, controlled by valve 24,connects fractionating tower 22 at thebottom to residuum tank 26. Pipe21, controlled by valve 28, connects residuum tank 26 at the bottom to afuel oil storage not shown. Pipe 64, with a U bend gas trap 63, connectsfractionating tower 22 just above separator plate 62 to the suction sideof pump 66. The flow of oil through pipe 64 is controlled by valve 65.Pipe 68, controlled by valve 61, connects the discharge side of pump 66to an upper section of reactionv chamber I5. Pipe II, controlled byvalve I0, connects reaction chamber I5 at the bottom to pipe 25.

Pipe 29 connects fractionating tower 22 at the top to condenser coil 3|.Condenser coil 3| is stationed in condenser box 30. Pipe 32 connectscondenser coil 3| to gas separator 33. Pipe 34, controlled by valve 35,connects gas separator 33 to a gas storage tank not shown. Pipe 36connects gas separator 33 to a gasoline or motor fuel storage tank 31.Pipe 38, controlled by valve 39, connects gasoline storage tank 31 atthe bottom to a storage not shown.

Pipe 40 is connected to fiues 52 and 53. Pipe 4 I, controlled by valve42, connects pipe 40 to the inlet of pump 45. Pipe 43, controlled byvalve 44, connects pipe 4| to a source of atmospheric air, also to asource of nitrogen gas, carbondioxide or carbon-monoxide, through branchpipe 60, controlled by valve 6|. Pipe 46 connects the discharge side ofpump 45 to heater coil 48.

Heater coil 48 is stationed in the upper section of heater or furnace41. Heater or furnace 41 is provided with an oil or gas burner 49. Pipe50, controlled by valve 5|, connects heater coil 48 to the lower sectionof reaction chamber I5.

The preferred process as carried out in the apparatus just describedis'as follows:

Hydrocarbon oil, such as naphtha, lamp oil distillates, gas oil stock,petroleum oil residuum, or crude petroleum oil, contained in tank 3, iscaused to flow through pipe 4and into the suction side of pump 6, therate of flow being governed by operation of valve 5. Pump 6 dischargesthe hydrocarbon oil to be processed in a regulated stream flow, under apressure which may range from approximately 50 pounds to as high as 1000pounds gauge or higher, through pipe 1, heat exchanger 8, pipe 9, heatercoil II, pipe I3, and into the vaporizing section of reaction chamberl5, wherein a residual oil is separated from the vaporized portion. Thepressure maintained on the uil passing through heater coil I I iscontrolled by pressure regulating valves I4 and 2 I. The residual oilwhich collects in the lower section of chamber I5 is continuously orintermittently withdrawn into residuum tank 26 through pipes II and 25,controlled by valve I0. The oil passing through heater coil II is heatedto an oxidizing reaction temperature, that is, to a temperature whererapid oxidation may be effected without molecular disruption when thevaporized portion is mixed with an aerii'orm fluid containing pref-.erably from approximately 5 to 18 per cent by volume free oxygen. Thetemperature employed to heat the oil being processed preferably rangesfrom approximately 800 to 1300 F., depending upon the stock treated andproducts desired, al-

though higher temperatures may be employed when high velocities aremaintained.

The pressure on the heated oil stream may be reduced to approximately 50to 300 pounds more or less, as it passes through pressure regulatingvalve I4, the exact reduction in pressure depending upon the boilingrange of the oil and the temperature to which it is heated. For oilswith relatively high boiling ranges, such as petroleum oil residua orgas oil distillate, a pressure of 50 to 100 pounds gauge more or lessmay be maintained in heater coil II, as well as in reaction chamber I5,controlled by valve 2I, while a pressure of 100 to 300 pounds or moremay be employed in reaction chamber l5 when certain grades of lamp oildistillate or naphtha are being processed to increase theanti-detonating characteristics thereof.

In the vaporizing section of reaction chamber I5 the vaporized oil ismixed with an aeriform fluid containing, as heretofore stated,preferably from approximately 5 to 18 per cent by volume free oxygen,which has been preferably heated to a temperature ranging from 800 to1300 F., and in quantities suflicient to reduce the hydrogen content ofthe oil to preferably approximately 14.3 per cent by weight and, to notless than 9 per cent by weight. The volume of aeriform fluid employedvaries through a wide range, depending upon the grade and chemicalcomposition of the oil to be processed.

For example, certain naphtha stocks derived from paraflln base crudepetroleum oil, consisting principally of hydrocarbons of the paraffinseries (CnH2n-1-2), may require as much as 300 cubic feet of theaeriform fluid (calculated at 0 C. and 760 mm. pressure) containing,say, 17 per cent by volume oxygen per gallon of stock, to produce amotor fuel or gasoline stock having an octane" number of 80 to 90. Forcertain distillates derived from an asphalt base crude petroleum oil, aslittle as 10 cubic feet of the aeriform fluid, containing fromapproximately 5 to 18 per cent by volume oxygen per gallon of stock, maybe used to produce a motor fuel or gasoline stock with an octane" numberranging from '70 to 90.

Aeriform fluid or products of combustion from furnaces I0 and 41,containing from approximately 5 to 18 per cent by volume oxygen, arecaused to pass from the flues 52 and 53 into pipe 40. From pipe 40 theflue gases pass through pipe M and then into the inlet side of pump 45,the rate of flow being regulated by operation of valve 42. By means ofpipe 43 and branch pipe 50, controlled by valve 44 and valve GIrespectively, the oxygen content of the flue gases may be increased ordecreased to obtain the required oxygen concentration for the oil thatis being processed, pipe 43 being connected to a source of nitrogen gas,carbondioxide or like gases, also to a source of atmospheric air. Pump45 discharges the aeriform fluid, containing the required oxygenconcentration, through pipe 46, heater coil 48, pipe 50 controlled byvalve 5 I, and then into the lower section of reaction chamber I5,wherein it is mixed with the vaporized portion of the oil coming fromheater coil II through pipe I3.

The aeriform fluid passing through heater coil 48 is preferably heatedto a temperature ranging from approximately 800 to 1300 F. or higher,this temperature depending upon the temperature of the vaporized oilentering reaction chamber I5, which is so regulated that the resultanttemperature of the mixed vaporized oil and heated aeridizing ordehydrogenation reaction has been added, will be approximately 800 to1100 F. for the production of a motor fuel or gasoline stock to have anoctane number of approximately 73 to 80, and approximately 1100 to 1300F. or higher if a motor fuel or gasoline stock having an octane numberof, say, to is desired.

The oil vapor, separated from the unvaporized portion of the oil beingprocessed, mixed with the aeriform fluid, passes up through contactmaterial IS in reaction chamber I5, wherein the oil is dehydrogenated tothe required degree, cracked and reformed with the production of gaseousproducts, high boiling oils and a motor fuel having anti-detonatingcharacteristics to the required degree. From reaction chamber I5 theproducts of the dehydrogenation, cracking and reforming reaction, andspent aeriform fluid, pass through pipe I9, heat exchanger 8, pipe 20,pressure relief valve 2| where the pressure may be reduced toapproximately atmospheric, and then into the lower section offractionating tower 22.

In fractionating tower 22 the higher boiling oils are separated byfractionation from the aeriform products and the motor fuel produced. Ahigher boiling distillate collects on separator plate 62 andcontinuously passes out of fractionating tower 22 through pipe 64 intothe suction side of pump 66, the rate of flow being controlled by valve65. The boiling range of the distillate collecting on separator plate 62may range from about 300 to 600 F., depending upon the oil beingprocessed and the products desired. Pump 66 discharges this higherboiling distillate, which is composed collects in residuum tank 26,together with the residual oil separated in the vaporizing section ofreaction chamber I5. The higher boiling residual oils which collect intank 26 may be conducted to other storage not shown through pipe 21,controlled by valve 28, after which they may be distilled and thedistillate returned to the system and processed for the furtherproduction of motor fuel or gasoline stock, and/or marketed as a fueloil.

The gasoline or motor fuel produced in vapor form, mixed with theothergaseous products, passes from the top of fractionating tower 22through pipe 23 and into condenser coil 3 I, which is stationed incondenser box 30. A cooling fluid, such as water or brine, flows throughcondenser box 30, whereby the major portion of the motor fuel iscondensed to a liquid. From condenser coil 3| the condensed motor fueland gaseous products pass through pipe 32 and into gas separator 33,wherein the liquid motor fuel is separated from the gaseous products andpasses through pipe 36, and is collected in tank 31.

The gaseous products, containing a certain percentage of the motor fuel,pass through pipe 34, controlled by valve 35, to an absorber not shown,therein the motor fuel retained by the gaseous products is separated byabsorption methods known in the, art, and thereafter returned and mixedwith the motor fuel or gasoline stock contained in tank 31. The motorfuel which collects in tank 31 is conveyed to other storage not shown bypipe 38, controlled by valve 39, and may be thereafter treated by knownpuri- 7 fication methods to produce a water white gasoline or motor-fueloil stock with high anti-detonating characteristics, or it may beblended with other gasoline stocks to increase the anti-detonatingcharacteristics, as heretofore stated.

The term marketable fuel oil as used in the specification and claims ofthis application is to be taken to mean a liquid hydrocarbon fuel oil asdesignated by the Bureau of Mines Technical Paper 323-B for Bunker FuelOil of the A, "13 or C grades.

While the process herein described is well adapted for carrying out theobjects of the present invention, it is to be understood that variousmodifications and changes may be made without departing from the spiritof the invention, such, for example, as the use of other forms ofelongated heaters or reaction chambers, and the invention includes allsuch modifications and changes as come within the scope of the appendedclaims.

I claim:

1. A method of processing hydrocarbon oil for the'production of motorfuel and a Bunker fuel oil, the steps which comprise, heating the oilunder super-atmospheric pressure to a cracking temperature ranging fromapproximately 800 to 1300 F., passing the heated oil into a vaporizingzone and separating a vaporized portion of the oil from a primaryresidual oil; combining with the vaporized portion of the oil anaeriform fluid having a free oxygen content from 5 to approximately 18per cent by volume, in quantities suflicient to reduce the hydrogencontent of the vaporized oil to at least 14.3 per cent and to not lessthan 9 per cent by weight; passing the combined mixture of vaporized oiland aeriform fluid through a reaction zone at temperatures ranging fromapproximately 800 to 1300 F., and then separating by fractionationaeriform products, motor fuel and a higher boiling distillate from asecondary residual oil; combining the separated secondary residual oilwith the primary residual oil to form Bunker fuel oil.

2. A method of processing hydrocarbon oil for the production of motorfuel anda Bunker fuel oil, as in claim 1, in which the aeriform fluid isair mixed with an inert gas.

3. A method of processing petroleum oil residuum for the production ofmotor fuel and a Bunker fuel oil, as in claim 1.

4. A method of processing hydrocarbon oil for the production of motorfuel and a Bunker fuel oil, as in claim 1, in which the pressure on theheated oil passing into the vaporizing zone is reduced to approximately50 to 300 pounds.

5. A method of processing hydrocarbon oil for the production of motorfuel and a Bunker fuel oil. as in claim 1, in which the separated higherboiling distillate is continuously returned to the reaction zone andfurther cracked by thermo molecular decomposition for the furthercontinubus production of motor fuel and secondary residual oil.

6. A method of processing hydrocarbon oil for the production of motorfuel and a Bunker .fuel

oil, the steps which comprise, heating the oil under superatmosphericpressure to a cracking temperature ranging from approximately 800 to1300 F., passing the heated oil into a vaporizing zone and separating avaporized portion of the oil from a primary residual oil; combining withthe vaporized portion of the oil an aeriform fluid having a free oxygencontent ranging from 5 to approximately 18 per cent by. volume, in anamount which will improve the anti-detonating characteristics of thevaporized portion of the oil; passing the combined mixture of vaporizedoil and aeriform fluid through a reaction zone at a temperature rangingfrom approximately 800 to 1300 F., fractionating the reaction productsand separating aeriform products, motor fuel and a higher boilingdistillate from a secondary residual oil, combining the separatedsecondary residual oil with the primary residual oil to form Bunker fueloil. 7. A method of converting high boiling hy drocarbon oil into lowboiling hydrocarbon oil and a Bunker fuel oil, comprising the steps ofheating an elongated confined stream of the high boiling hydrocarbon oilto a temperature ranging from approximately 800 to 1300" F., vaporizinga portion of the oil so heated in an enlarged zone and separatingtherefrom a primary residual oil, then introducing into thevaporizedportion of the oil a heated gaseous mixture having a free oxygen contentfrom 5 to approximately 18 per cent by volume, in quantities suificientto reduce the hydrogen content of the vaporized portion of the oil to atleast 14.3 per cent and to not less than 9 per cent by weight;fractionating the reaction products and separating aeriform products,motor fuel and a higher boiling distillate from a secondary residualoil; combining the separated secondary residual oil with the primaryresidual oil to form Bunker fuel oil.

8. A method of processing hydrocarbon oil for the production of motorfuel and a Bunker fuel oil, the steps which comprise, heating the oilunder superatmospheric pressure to a cracking temperature ranging fromapproximately 800 to 1300 F., reducing the pressure and passing the oilinto a vaporizing zone and separating a vaporized portion of the oilfrom aprimary residual oil; combining with the vaporized portion of theoil an aeriform fluid having a free oxygen content from 5 toapproximately 18 per cent by volume, in quantities sufficient to reducethe hydrogen content of the vaporized oil to at least 14.3 per cent byweight and to not less than 9 per cent by weight; passing the combinedmixture of vaporized oil and aeriform fluid through a reaction zone attemperatures ranging from approximately 800 to 1300 F., and thenseparating by fractionation aeriform products, motor fuel and a higherboiling distillate from a secondary residual oil; combining theseparated secondary residual oil' with the primary residual oil to formBunker fuel oil.

MARVIN L. CHAPPELL.

